Clinical utilization of pulmonary artery catheter monitoring

Since the introduction of PA catheter monitoring in 1970, the applications for it have dramatically broadened. PA catheters are used to obtain hemodynamic data for the assessment, monitoring, and therapeutic management of critically ill, high-risk surgical patients. Because of potential complications associated with PA catheter monitoring, numerous editorials and articles have questioned the procedure's risk-to-benefit ratio. These articles address the inadequacy of outcome data and suggest no demonstrated benefit from PA monitoring. Subgroups of patients have been identified, however, in whom PA monitoring data altered clinicians' assessment and management. In spite of a study by Rao and colleagues implying that PA catheter monitoring can decrease the mortality rate in critically ill patients, no scientific study has confirmed this impression. A more recent article evaluated the impact of PA catheter monitoring on mortality with emphasis on how the information is used. This prospective study noted a potential benefit from PA catheter monitoring in a protocol group, but the limited sample size and selection criteria prevent definitive conclusions. Unfortunately, many of the reported studies are retrospective, nonrandomized, unblinded, limited in scope or size, and founded on subjective end points. Careful evaluation of individual studies is mandatory to avoid overinterpretation of the conclusions. Understanding the limits of PA monitoring is needed for therapy to be successful. Problems may stem not from technology but from the knowledge and expectations of clinicians. "Human" complications from inadequate understanding of the physiological data is not uncommon. Measured pressures by themselves can be misleading; indeed use of absolute numbers rather than trends or relative changes in the values monitored can compromise clinical assessment. Overzealous acceptance and utilization of any quantitative measurement without sound clinical judgment is fraught with failure.